The process of intelligent interaction through brain machine interface requires quick and accurate extraction of Electroencephalogram (EEG) signals. However, the accuracy of signal classification varies with the signal extraction location. Is there a universal rule to follow to determine the optimal extraction location? This paper investigates the possibility of a universal rule to determine optimal extraction location through Welch, Support Vector Machine and Euclidean distance algorithms. The motor imagery EEG signals of 40 subjects were extracted and the classification correct rates of brain electrode signals in different positions were analyzed using Welch and Support Vector Machine algorithms. Then the electrodes were sorted according to the correct rate, and finally three pairs of electrodes with the highest correct rate were obtained. For comparison, this paper proposed another method of searching for the optimal electrodes, namely the combination of Welch and Euclidean distance algorithms. Ultimately, a similar conclusion was drawn from the above two methods: T3/T4, F3/F4 and C3/C4 electrodes usually have high classification accuracy. This result is helpful for quick customization of optimal brain electrode placement.
The transformation mechanism and kinetics of 2-chloro-1,1,2-trifluoroethyl-difluoromethyl-ether (CTDE, CHF2OCF2CHFCl) triggered by OH radicals were researched by DFT methods and canonical variational transition state theory. The computational rate constant including small-curvature tunneling correction was in commendable agreement with the experimental data. Two hydrogen abstraction channels to form the alkyl radicals of C·F2OCF2CHFCl and CHF2OCF2C·FCl were observed, and the formation of CHF2OCF2C·FCl was more favorable than C·F2OCF2CHFCl in kinetics and thermodynamics. Subsequent evolution of CHF2OCF2C·FCl in the presence of NO and O2 indicated that the organic nitrate (CHF2OCF2CONO2FCl) was the stable product. The dechlorinate of alkoxy radical (CHF2OCF2C(O·)FCl) was the most favorable degradation channel and the estimated ozone depletion potential for CTDE relative to CFC-11 was 0.0204, which could lead to a consequence of ozone depletion. Computed atmospheric lifetime for CTDE was 3.69 years by considering the combined contributions from OH radicals and Cl atoms. The total radiative forcing and global warming potential of CTDE were respectively 0.547 W m-2 ppbv and 628.58 (100 years) at 298 K, suggesting that the contribution of CTDE to the greenhouse effect is moderate.
The mechanisms of Cp*Rh(OAc)2-catalyzed coupling reaction of N-methoxybenzamide with alkyl-terminated enyne have been investigated by density functional theory (DFT) calculations. With the addition of NaOAc and changing solvent, the product transforms from lactam P1 in reaction A to iminolactone P2 in reaction B, due to the formed stable OAc- coordinated intermediate. The electronic effect and steric effect account for the observed regioselectivity in reaction B collectively.
Intermittent rivers are prevalent in many countries across Europe and in Mediterranean countries outside Europe, but little is known about the temporal evolution of intermittency characteristics and their relationships with climate variability. In this study, a trend analysis is performed on the annual and seasonal number of zero-flow days, the maximum duration of dry spells and the mean date of the zero-flow events, on a database of 452 rivers in European and in Mediterranean countries outside Europe, with varying degrees of intermittence. In addition, the relationships between flow intermittence and climate are investigated using the Standardized Precipitation Evapotranspiration Index (SPEI) and six climate indices describing large scale atmospheric circulation. Results indicated a strong spatial variability of the seasonal patterns of intermittence and the annual and seasonal number of zero-flow days, which highlights the controls exerted by local catchment properties. Most of the detected trends indicate an increasing number of zero-flow days which also tend to occur earlier in the year, in particular in Southern Europe. The SPEI is found to be strongly related to the annual and seasonal zero-flow day occurrence in more than half of the stations for different accumulation times between 12 and 24 months. Conversely, there is a weak dependence of river intermittence with large-scale circulation indices. Overall, these results suggest increased water stress in intermittent rivers that may affect their biota and biochemistry and also reduce available water resources.
In this paper Spontaneous Process Algorithm (SPA) is proposed to solve optimal reactive power problem. Formulation of the projected algorithm is done by imitating the process done during nuclear fission and fusion. Every item of a nucleus attribute symbolizes each solution variable. Sequence of operators directs the nucleus and in order to avoid the local optimum it will imitate the dissimilar condition of reaction. In the exploration space nucleus symbolizes the variables and potential solution. Levy flight has been intermingled in the procedure to enhance the diversification and intensification in the search. Spontaneous Process Algorithm (SPA) has been tested in standard IEEE 14, 30, 57,118,300 bus test systems and simulation results show the projected algorithm reduced the real power loss comprehensively and there is increase in percentage of reduction of real power loss.
Scale and tempo of brain expansion in the course of human evolution implies that this process was driven by a positive feedback. The ‘cultural drive’ hypothesis suggests a possible mechanism for the runaway brain-culture coevolution wherein high-fidelity social learning results in accumulation of cultural traditions which, in turn, promote selection for still more efficient social learning. Here we explore this evolutionary mechanism by means of computer modeling. Simulations confirm its plausibility in a social species in a socio-ecological situation that makes the sporadic invention of new beneficial and cognitively demanding behaviours possible. The chances for the runaway brain-culture coevolution increase when some of the culturally transmitted behaviours are individually beneficial while the others are group-beneficial. In this case, ‘cultural drive’ is possible under varying levels of between-group competition and migration. Modeling implies that brain expansion can receive additional boost if the evolving mechanisms of social learning are costly in terms of brain expansion (e.g., rely on complex neuronal curcuits) and tolerant to the complexity of information transferred, that is, make it possible to transfer complex skills and concepts easily. Human language presumably fits this description. Modeling also confirms that the runaway brain-culture coevolution can be accelerated by additional positive feedback loops via population growth and lifespan extension, and that between-group competition and cultural group selection can facilitate the propagation of group-beneficial behaviours and remove maladaptive cultural traditions from the population’s culture, which individual selection is unable to do.
In this study, we used two common ant species (Lasius niger and L. neoniger) to assay how they translate variation in the diet (both in composition and frequency) into growth. We measured colony development for over 8 months and measured several phenotypic traits of the worker caste, and examined whether forager preference corresponded with diet quality. Individuals (workers) and colonies (superorganisms) increased in size with increasing amounts of protein in the diet, and as a function of how much food was available. Optimal colony growth was a balance between survival and growth, and each of these were maximized with different nutrient regimes. Interestingly, forager preference was not totally aligned with the diet that maximized colony growth. Our results highlight that: 1) organism and superorganism size are controlled by the same nutrients, and this may reflect a common molecular basis for size across life’s organizational levels, 2) there are nutrient trade-offs that are associated with life-history trade-offs, likely leading to selection for a balanced diet, and 3) the connection between the preference of foragers for different nutrients and how nutrient combinations affect colony success and demographics are complex and only beginning to be understood.
Study of species’ ecological niches through evolutionary history can elucidate speciation mechanisms, yet current comparative phylogenetic methods consistently overestimate niche evolution. Here we propose a method by which to characterize species’ fundamental ecological niches for comparative phylogenetic analysis using a bin-based approach that incorporates uncertainty in niche estimates. Simulation analysis using a traditional characterization method (median value calculated from species’ known occurrences) estimated a significantly higher rate of niche evolution than using our proposed method, and differences in rate estimates were consistent regardless of the number of simulated taxa in a phylogeny. We also demonstrate how to perform ancestral state reconstructions under the new coding system; reconstructions are performed for each bin individually, and ancestral fundamental niches inferred by smoothing each node’s reconstructions across all bins. Finally, we provide a worked empirical example of our method, investigating ecological niche evolution in 34 species of New World orioles (Icterus spp.). Ecological niches were generally conserved in the group, and only a few lineages appear to have experienced niche reduction and specialization.
Aeroponics or Soil-less agriculture is a relatively new and recent type of practice, where plants are grown without soil while nutrient-rich water is provided via an atomized spray system to the suspended roots. Spray nozzles are easy-to-use in supplying water (and fertilizers) to (mainly) the roots and root hairs of the desired crop (or plant) for production. We characterize a spray nozzle delivering water vertically above against the gravity by measuring, experimentally, its (a) spray drift, (b) spray height, (c) maximum spray angle, (d) spray width, and (e) droplets sizes. Experiments were carried out at different inlet pressures and a majority of the above mentioned parameters were obtained by processing the images captured using digital (or high speed) camera, sometimes along a plane lighted by a high-power laser source. We also studied the spray (or jet) behaviour at different vertical heights and different horizontal planes using a unique polythene sponge method. We studied the mass flow rate, the mass of water absorbed, and droplet size dynamics (as a function of time and pressure) using this method. A mathematical model is proposed to understand such flows, whose results matched reasonably well with the experimental values. We believe that this study can be extrapolated to other nozzles (or sprays) to obtain similar characteristic parameters. A study was conducted on the characterization of “Plant-water uptake”. This study hence is critical in selecting the desired spray system for a given canopy. The research conducted here would be crucial in designing an Aeroponic system in a controlled agricultural environment.
1. Wild animal populations typically harbour multiple parasite species, which can interact in various ways depending on the species involved and the state of the host upon infection. While many pairwise parasite interactions and within-guild parasite communities have been characterised, understanding how an interaction network spanning multiple parasite groups might be mediated has been less commonly explored. 2. We aimed to characterise parasites associations across guilds in a wild population of a model species, allowing for comparisons with existing laboratory-based research, and better understanding of how any observed associations might manifest within the host. 3. We used cross-sectional data from an island population of the house mouse, Mus musculus domesticus, to identify associations between a broad range of parasite species, including blood-borne microparasites, arthropod ectoparasites, and gastrointestinal and hepatic helminths. 4. Every recorded species was found to exist within a framework of positive and negative associations, involving multiple between-guild associations, and with the under-studied helminth species Calodium hepaticum playing a central role. 5. This study highlights the need to account for as many infections as possible when studying naturally infected populations, due to the prevalence of inter-species associations. Various potential mechanisms, including immunological and ecological, are suggested to explain how these associations might occur. Comparisons with analogous laboratory research from the same species are explored. A need for longitudinal study to determine causality of interactions is highlighted.
In this article, we present a double side highly isolated triple band-notched UWB MIMO antenna for short-range wireless communication applications. The proposed MIMO antenna design provides a UWB band with the notched band at the IEEE INSAT C band satellite communication and WLAN band (4.6–5.9 GHz), the X band uplink and downlink satellite communication (7.70–8.43) and (10.3-10.98 GHz). It has double side placement of polygon-shaped radiating elements, and an inverted L-shaped stub to obtain high isolation between radiating elements. The proposed antenna has a size of 18 × 28 mm2, which operates from 3 to 12 GHz. The antenna characteristics such as isolation between radiating elements, S11/S22, gain, and radiation characteristics are studied. The proposed MIMO antenna has isolation of >19 dB, 0-7.5 dBi peak gain and almost radiation pattern over the entire operating frequency band with pattern diversity. Furthermore, MIMO diversity performance was investigated using an ECC, diversity gain, multiplexing efficiency, TARC, and CCL. The proposed UWB MIMO antenna has very low ECC of 0.0025, and DG of >9.9, over the entire operating band (3-12 GHz). Also, the real-time indoor short-range communication capability of the proposed MIMO antenna demonstrated by using the NI 802.1 framework
There is a rich amount of information in co-occurrence data that could be used to understand community assembly. This proposition first envisioned by Forbes (1907) and then Diamond (1975) prompted the development of numerous modelling approaches (e.g. null model analysis, co-occurrence networks and, more recently, joint species distribution models). Both theory and experimental evidence support the idea that ecological interactions may affect co-occurrence, but it remains unclear to what extent the signal of interaction can be captured in observational data. The time is now ripe to step back from the statistical developments and critically assess whether co-occurrence data really is a proxy for ecological interactions. In this paper we present a series of arguments based on probability, sampling, food web and coexistence theories supporting that significant spatial associations between species (or the lack of) is a poor proxy for ecological interactions. We discuss appropriate interpretations of co-occurrence, along with potential avenues to extract as much information as possible from such data.
Hypertension is a major risk factor for cardiovascular diseases, with high prevalence in low- and high-income countries. Among the various antihypertensive therapeutic strategies, synthetic Angiotensin I-converting enzyme inhibitors (ACEI) are one of the most used pharmacological agents. However, their use in hypertension therapy has been linked to various side effects. In recent years considerable research has been performed on the use of food-derived ACEI peptides (ACEIp) as antihypertensive agents. Although promising, the industrial production of these ACEIp through conventional methods, such as chemical synthesis and enzymatic hydrolysis of food proteins, has been proven troublesome and expensive. Limitations to the large-scale production of ACEIp for functional foods and supplements can be overcome by producing the precursors of these peptides in heterologous hosts. Bacterial hosts have been the privileged choice, particularly to test the success of the genetic engineering strategies, but new platforms based on plants and microalgae have also been emerging. This work provides an overview of the state of antihypertensive therapy, focusing on ACEI, illustrates the latest advances on ACEIp research, and describes current genetic engineer-based approaches for the heterologous production of ACEIp for antihypertensive therapy.
In this paper I focus on the FDA regulation of medical treatments. As a matter of fact, since the advent of drug regulation in 1962, we have a variety of standards for testing the safety and the efficacy of treatments and products. I want to make explicit the reasons for explaining that variety. Here I argue that medical regulatory schemes are grounded on an implicit socio-political consensus on the risks involved by different medical interventions: the bigger the threat, the stricter the testing standards. Finally, by analysing the concept of risk, I claim that, from the point of view of regulators, innovative drugs might be not very different from medical devices or even surgical procedures, therefore lower testing standards are more defensible than what critics usually think.
In this paper, a highly robust antenna for omnidirectional circular polarized communication in the harsh environment at 2.45 GHz ISM frequency band is proposed based on a transparent structure. Circular polarization has been realized utilizing a combination of two magnetic and electric dipoles. The antenna is covered with a quarter wavelength layer of plexiglass to achieve desired robustness and visible light transparency. Meanwhile, it can integrate with solar cells because of the high transparency of glass to simultaneously propagate signals and harvest energy. The gain and bandwidth of the antenna are 1.7 dBi and 300 MHz, respectively. The antenna's axial ratio is achieved less than 3 dB within the bandwidth showing circular polarization behavior. The proposed compact antenna is numerically and experimentally analyzed and compared together, having a suitable agreement. In another aspect, the structure can give promising openings to enhance the propagating properties, which could generate critical advantages for real-world multifunctional applications.
The young water fraction (Fyw), the proportion of water younger than 2-3 months, was investigated in soil-, ground- and stream waters in the 0.56 Km2 sub-humid Mediterranean Can Vila catchment. Rain water was sampled at 5-mm rainfall intervals. Mobile soil water and groundwater were sampled fortnightly, using suction lysimeters and two shallow wells, respectively. Stream water was dynamically sampled at variable time intervals (30 minutes to 1 week), depending on flow. A total of 1,529 18O determinations obtained during 58 months were used. The usual hypothesis of rapid evapotranspiration of summer rainfall could not be maintained, leading to discard the use of an “effective precipitation” model. Soil mobile waters had Fyw up to 34%, while in ground and stream were strongly related to water table and discharge variations, respectively. In stream waters, due to the highly skewed flow duration curve, the flow-averaged young water fraction (F*yw) was 22.6%, whereas the time-averaged Fyw was 6.2%. Nevertheless, both F*yw and its exponential discharge sensitivity (Sd) showed relevant changes when different 12-month sampling periods were investigated. The availability of Sd and a detailed flow record allowed us to simulate the young water fraction that would be obtained with a virtual thorough sampling (F**yw). This showed that underestimation of F*yw is associated with missing the sampling of highest discharges and revealed underestimations of F*yw by 25% for the dynamic sampling and 66% for the weekly sampling. These results confirm that the young water fraction and its discharge sensitivity are metrics that depend more on precipitation forcing than on physiographic characteristics, so the comparisons between catchments should be based on mean annual values and inter-annual variability. They also support the dependence of the young water fraction on the sampling rate and show the advantages of flow-weighted F*yw. Water age investigations should be accompanied by the analysis of flow duration curves. In addition, the simulation of F**yw is proposed as a method for checking the adequacy of the sampling rate used.
This is a fundamental study addressing the articulation of knowledge from the context of the fourth industrial revolution (Industry 4.0). Industry 4.0 employs embedded systems (e.g., cyber-physical systems) to perform cognitive tasks. These systems cannot work without applying digitized knowledge. As a result, the digitization of knowledge-intensive activities (knowledge acquisition, representation, dissemination, utilization, and management) is critical for Industry 4.0. Before digitizing the knowledge and knowledge-intensive activities, a fundamental question arises: What is knowledge in Industry 4.0? This study answers this question. In doing so, this study first reviews the definitions of knowledge reported in the extant literature of epistemology, engineering design, manufacturing, organization science, information science, and education science. This study then defines that a piece of knowledge consists of three elements, namely, claim, provenance, and inference. Such a definition helps overcome the circularity and ambiguity in the definitions of knowledge reported so far. This definition results in four types of knowledge, namely, definitional, deductive, inductive, and creative knowledge. These types of knowledge are exemplified using some real-life scenarios relevant to engineering design and manufacturing. The exemplified pieces of knowledge are also represented by using knowledge graphs (concept maps) so that the contents can easily be digitized for human and machine learning. The outcomes of this study are the fundamentals based on which more sophisticated methods and tools can be developed to perform the cognitive tasks relevant to Industry 4.0.
We present a numerical method for simulating 2D flow through a channel with deformable walls. The fluid is assumed to be incompressible and viscous. We consider the highly viscous regime, where fluid dynamics are described by the Stokes equations, and the less viscous regime described by the Navier-Stokes equations. The model is formulated as an immersed boundary problem, with the channel defined by compliant walls that are immersed in a larger computational fluid domain. The channel traverses through the computational domain, and the walls do not form a closed region. When the walls deviate from their equilibrium position, they exert singular forces on the underlying fluid. We compute the numerical solution to the model equations using the immersed interface method, which preserves sharp jumps in the solution and its derivatives. The immersed interface method typically requires a closed immersed interface, a condition that is not met by the present configuration. Thus, a contribution of the present work is the extension of the immersed interface method to immersed boundary problems with open interfaces. Numerical results indicate that this new method converges with second-order accuracy in both space and time, and can sharply capture discontinuities in the fluid solution.